Listen closely to the president of the United States these days, and you will hear the creaks and groans of an American male nearing the midcentury mark.

Barack Obama will turn 50 just a few months from now, on August 4 — a milestone that already seems to be shadowing the presidential mood. In recent speeches, references to the burdens of office are woven constantly with references to the burdens of middle age.

Take a look, he tells audiences, at the bags under his eyes. He sometimes mentions his daughters — racing, it seems to him, out of childhood and into adolescence. Then, invariably, he mentions his hair. Perhaps you have noticed: It is turning gray. (See: Michelle Obama: Obama doesn't dye his hair)

“We’ve been governing for 2½ years,” Obama told supporters on a conference call this month. “I don’t look that young anymore. I’m grayer, I have bags under my eyes, but that core spirit is still there.” (See: Campaign trail a gray area for Obama)

The same refrain was heard last week in Chicago, at back-to-back fundraisers at which Obama repeated himself in nearly identical language. “You know, your candidate is a little grayer now,” he told supporters. “Some of the excitement of something entirely new is not going to be there, and I’ve got some dents and dings in the fender. But that vision hasn’t changed. What we care about hasn’t changed. Our commitments should not have changed.” (See: Barack Obama kicks off 2012 campaign in Chicago)

The autumnal notes in Obama’s stump speech suggest that an older-but-wiser motif is going to be an important part of his public persona this year, as he presents himself as a sensible protector of progressive values in his confrontations with congressional Republicans, and next year, as he asks voters to trust him with another four years in office.

The language apparently has its origins at least partly in Obama’s own midlife musings.

Valerie Jarrett, the White House senior aide who is closest to Obama personally, said in an interview that the trend began with spontaneous references to graying hair and the challenges of public life that cropped up in private settings, or in impromptu comments to audiences. (See: Obama '12: Same cast, different story)

Over time, she said, presidential speechwriters began inserting the language into his formal remarks.

Jarrett said Obama is not brooding about his lot in life, much less facing the stereotypical male midlife crisis — no chance he’ll be trading in the black limousine for a red Corvette in the presidential motorcade. Obama, his friend said, is simply sharing natural ruminations that might strike anyone approaching age 50.

“It’s not weighing on him — he’s very comfortable with the stage of life that he’s in,” Jarrett told POLITICO. “He shares it in a very lighthearted way. It’s just a reality. It’s a common feeling that many men and women of his age experience as life moves on.”

Obama’s two baby boomer predecessors certainly wrestled with the process.

Before former President George W. Bush returned to Texas in 2008, he told reporters that when he looked in the mirror, “I’m not going to regret what I see — except maybe some gray hair.”

Tony Fratto, who served as Bush’s deputy press secretary, said age didn’t faze Bush. Presidents, he added, “can’t hide anything (about aging) so they get fatalistic about it.”

That seemed true of Bill Clinton, whose salt and pepper hair turned silver during his presidency. He once admitted to feeling a little jealous of his then British counterpart Tony Blair for maintaining his youth. “He’s seven years younger than I am and has no gray hair, so I resent it, but there doesn’t seem to be anything I can do about it,” Clinton said.

Never one to minimize the milestone in his life, Clinton presided over a massive 50th birthday celebration at Radio City Music Hall that was broadcast live to some 80 locations, as well as a big party in which it was later revealed that Monica Lewinsky squeezed him in the groin in the receiving line.

And he freely admitted that the birthday made him sense his own mortality, describing in one interview how “becoming 50 gives me more yesterdays than tomorrows.”

But public musings about aging still seem striking coming from Obama. As he noted himself in recent remarks, his 2008 campaign was defined by an aura of youth — the energy of his student and 20-something supporters, the appeal for a generational turning from a candidate who was himself the fifth-youngest man to assume the presidency (after Theodore Roosevelt, John F. Kennedy, Clinton and Ulysses S. Grant).

And even before he burst onto the national scene with his keynote address to the Democratic National Convention in 2004, Obama’s career had been marked by youthful achievement: president of the Harvard Law Review in his 20s, a law professor and state legislator in his 30s and to the U.S. Senate and the presidency in his 40.

Now, however, Obama seems to be inviting audiences to see him as a middle-aged man of experience — bent and even bloodied by his Washington tenure but not broken by it.

Speaking in New York City this month to the National Action Network, run by Al Sharpton, Obama recalled addressing the group for the first time in 2007. “I was looking at some pictures; I looked really young back then,” he said, after repeating his familiar “gray hair” line.

Earlier on the same day, he told supporters at a town hall meeting in Pennsylvania that despite his own gray hair, “you guys still look great. I’m a little worn down.”

No line appears regularly in presidential speeches by accident, and some observers see a clear strategic purpose to Obama’s references to his Washington battles and pledges that he has not lost his original idealism.

“So many people in 2008 saw a commonality with him, and some of those people have been disappointed in him,” said Joe Tuman, a political science professor at San Francisco State University. “Anything he can do to reconnect to those people is wise.”

Obama’s comments on growing older “make him human,” Tuman said. “The one thing we share is that we all get old.”

Although a private person who has carefully guarded his family’s privacy, Obama over time has revealed a smattering of other details of his personal life that have helped the Every Man appeal.

His battle to quit smoking, for example, has been well chronicled. His interest in sports — he watches ESPN every morning at the gym — has been demonstrated by his well-publicized NCAA basketball brackets and his seeming willingness to greet every possible championship team at the White House.

And he has even made more than a few lighthearted references to his strong-willed wife, Michelle, jokingly recounting a conversation last fall on the midterm stump this way: “…And she’s telling me what I should do — It’s true,” he told a crowd in Ohio, to laughter. “You think I’m joking. I’m not. I have witnesses.”

Earlier this year, when the subject of her husband’s graying hair came up — she was asked if he dyed it — Michelle Obama seemed impatient with the whole subject.

“I think that if he would have known he would be president, he would have started dying his hair like 10 years ago,” the first lady said on NBC’s "Today" show.

But aging and its effects have become a persistent theme that comes up whether Obama’s talking about food — “I want everyone to know that when I was 20, I could order a 12-inch sub (sandwich),” he said at a photo-op at the Tastee Sub Shop in New Jersey last year — or his children growing up.

At the National Prayer Breakfast in February, Obama described his prayer life and joked that he asks for “patience as I watch Malia go to her first dance, where there will be boys.”

“Lord, have that skirt get longer as she travels to that dance,” Obama said in his remarks.

Jarrett chocks up Obama’s sentiments to feeling “wistful” about his daughters getting older.

Gloria Starr, a longtime image consultant, said the joke about his preteen daughter was “a way that he can interact on a very real level” with other parents. “Every day people worry about their age. They worry about their children growing up. It’s traumatic for anyone.”

At the same time, Julian Zelizer, a professor of history and public affairs at Princeton University, said “it’s hard to tell” if Obama is just oversharing his internal strife or if it’s simply “shrewd political theater.”

But, he said, “either way, those moments sometimes give voters a better sense of who the president is, rather than just the president. When presidents talk about issues like age and parenthood, sometimes it is also a way to appeal to others of his generation as well as more elderly Americans who can remember those moments.”

But does all this talk of aging risk losing the younger voters who flocked to his campaign in 2008?

It’s possible, says Tuman, that “to some extent he distances himself” from young voters. Four years later, he adds, “they’ll be looking at him as someone who’s old enough to be their father.”

Still, he added, Obama of all the candidates “probably has the best shot of connecting with them” because he also uses their language and has experience connecting with younger voters though social media.

At least one Republican presidential candidate — former Minnesota Gov. Tim Pawlenty — seems to see an opening.

“For a candidate, I am relatively young,” Pawlenty told InsideVandy.Com, a news outlet at Vanderbilt University. “I have a more recent connection to the younger generation than some have or might have had in the past.

But Pawlenty is a year older than Obama; another leading Republican candidate — former Massachusetts Gov. Mitt Romney — is 14 years older. Haley Barbour is 63, Newt Gingrich is 67.

Chances are Obama — gray hair and all — will again be the youngest candidate in the race.

Correction: An earlier version of this story misstated the age difference between President Obama and Mitt Romney. Romney is 14 years older.